In a multitude of commercial applications, it is common to employ a heavy-duty conveyor belt for the purpose of transporting product and material. The conveyor belts so employed may be relatively long, for example, on the order of miles, and represent a high cost component of an industrial material handling operation. Such conveyor belts can possibly be as large as ten feet wide, and possibly as thick as three inches. The main belt material generally is a moderately flexible elastomeric or rubber-like material, and the belt is typically reinforced by a plurality of longitudinally extending metal cables or cords, which are positioned within the belt and extend along the length thereof. Such conveyor belts are often used to transport bulk material below and/or above ground, for example, in mining applications. The conveyor belts and respective drives are susceptible to normal wear and tear as well as damage from the material being transported and/or harsh environmental conditions. In the event the conveyor belt suffers catastrophic damage or otherwise becomes inoperable, the costs of repairing the conveyor belt, cleaning up the spilt material, and related downtime are substantial.
A problem associated with the use of the metal reinforcing cords is that with continued use of the conveyor belts, over time, the cords tend to deteriorate. For example, there may be a crack in the conveyor belt elastomeric material that permits water or possibly even an acid, resulting from water reacting with the conveyed material, for example, to contact one or more of the cords and potentially leading to corrosion of the cords. Cord damage may also result from an aggressive impact of the product or material being transported on the conveyor. Deterioration may also occur from natural wear or possibly fatigue of the metal due to long continued use. Occasionally, the damage to the cord is a total break, while in other instances the damage to the cord may be a partial deterioration that simply weakens the belt.
Because the cords are concealed inside the elastomeric material of the belt, it is challenging to detect any damage. Unfortunately, when the damage is sufficiently severe such that it becomes outwardly visible, a catastrophic failure of the belt may occur. More commonly, the damage may result in a condition that would make further use of the belt dangerous. For this reason, among others, it has generally been a practice in the industry to overdesign the belts by providing an adequately large margin of error which enables the belt to function reasonably safely even if the reinforcing cords are moderately damaged.
Accordingly, it has become common practice to monitor the condition of the conveyor belt. The objective of the monitoring is to identify damage to the reinforcing cords of the conveyor belt so as to reduce the likelihood of complete failure as well as to provide timely repairs and other prophylactic maintenance. Monitoring effectively increases the life or longevity of the belt. In this regard, one common practice is to have an annual or bi-annual analysis conducted on the conveyor belt. To this end, typically a separate entity (e.g., outside consultant), other than the owner or user of the conveyor belt, such as the manufacturer of the conveyor belt or some other third party, will come on site and set up a monitoring system in order to collect data on the conveyor belt during use. Data will generally be collected for multiple revolutions of the conveyor belt and may take several hours to complete. Once the data is collected, the outside consultant will leave the on-site location and take the data to another, remote location for analysis. The data will then be reviewed and a report generated providing details on the condition of the conveyor belt and any recommended maintenance. Depending on the consultant, the analysis and report may take anywhere from a few days to a few weeks to complete.
Continuous monitoring systems have been developed that collect data on the conveyor system to determine damage and possibly inspect, repair, or replace portions of conveyor belts. Although continuous monitoring is utilized, such systems suffer from similar deficiencies as those described above. In particular, the data is typically sent to a remote site for analysis and reporting to determine the location of damage; is complicated and prone to subjective interpretations; and lacks a clear standard on which to base instructions for finding events to inspect, repair, or replace portions of the conveyor belt. Even if the data is analyzed locally, after the analysis, locations of the identified damage may be difficult to locate along the belt. Generally, the only reference points available from the belt are splice locations, which may be from about 100 feet to in excess of about 1500 feet apart, if not further, making the determination of the location of the identified damage challenging. With belts having multiple intermediate splices, locating the reference points for the damage events can be even more challenging for the belt operator or maintenance personnel. Additionally the time it takes for conventional sensor systems to initiate a higher level of protection may be as long as one complete revolution of the belt for a reference marker or event to pass by the belt monitor sensors.
Accordingly, there is a need in the industry for an improved conveyor belt monitoring system that correlates sensor damage maps to physical belt markings in order to minimize the time required to initiate cord damage monitoring and quickly and accurately locate damaged areas of the conveyor belt.